This Patch corrects a problem whereby the optimization to use a faster divide

instruction (for Intel Atom) was not being done by Clang, because
the type context used by Clang is not the default context.

It fixes the problem by getting the global context types for each div/rem
instruction in order to compare them against the types in the BypassTypeMap.

Tests for this will be done as a separate patch to Clang.

Patch by Tyler Nowicki.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165126 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Utils/BypassSlowDivision.cpp b/lib/Transforms/Utils/BypassSlowDivision.cpp
index ac18b7d5a058e4a111a0de600c1e3e0ab75d36be..821b588112d673db75398ce66ef7b87e2a87ad79 100644 (file)
--- a/lib/Transforms/Utils/BypassSlowDivision.cpp
+++ b/lib/Transforms/Utils/BypassSlowDivision.cpp
@@ -238,14 +238,24 @@ bool llvm::bypassSlowDivision(Function &F,
     if (!UseDivOp && !UseRemOp)
       continue;
 
+    // Skip division on vector types, only optimize integer instructions
+    if (!J->getType()->isIntegerTy())
+      continue;
+
+    // Get same type in global context
+    IntegerType *T = cast<IntegerType>(J->getType());
+    IntegerType *GT = IntegerType::get(getGlobalContext(), T->getBitWidth());
+
     // Continue if div/rem type is not bypassed
-    DenseMap<Type *, Type *>::const_iterator BT =
-      BypassTypeMap.find(J->getType());
-    if (BT == BypassTypeMap.end())
+    DenseMap<Type *, Type *>::const_iterator BI = BypassTypeMap.find(GT);
+    if (BI == BypassTypeMap.end())
       continue;
 
-    IntegerType *BypassType = cast<IntegerType>(BT->second);
-    MadeChange |= reuseOrInsertFastDiv(F, I, J, BypassType, UseDivOp,
+    // Get the bypass type in the original context
+    IntegerType *GBT = cast<IntegerType>(BI->second);
+    IntegerType *BT = IntegerType::get(J->getContext(), GBT->getBitWidth());
+
+    MadeChange |= reuseOrInsertFastDiv(F, I, J, BT, UseDivOp,
                                        UseSignedOp, DivCache);
   }